drivers/staging/ipack/ipack.c

   1 /*
   2  * Industry-pack bus support functions.
   3  *
   4  * (C) 2011 Samuel Iglesias Gonsalvez <siglesia@cern.ch>, CERN
   5  * (C) 2012 Samuel Iglesias Gonsalvez <siglesias@igalia.com>, Igalia
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the Free
   9  * Software Foundation; version 2 of the License.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/idr.h>
  15 #include <asm/io.h>
  16 #include "ipack.h"
  17
  18 #define to_ipack_dev(device) container_of(device, struct ipack_device, dev)
  19 #define to_ipack_driver(drv) container_of(drv, struct ipack_driver, driver)
  20
  21 static DEFINE_IDA(ipack_ida);
  22
  23 static void ipack_device_release(struct device *dev)
  24 {
  25         struct ipack_device *device = to_ipack_dev(dev);
  26         kfree(device->id);
  27         kfree(device);
  28 }
  29
  30 static inline const struct ipack_device_id *
  31 ipack_match_one_device(const struct ipack_device_id *id,
  32                        const struct ipack_device *device)
  33 {
  34         if ((id->format == IPACK_ANY_FORMAT ||
  35                                 id->format == device->id_format) &&
  36             (id->vendor == IPACK_ANY_ID || id->vendor == device->id_vendor) &&
  37             (id->device == IPACK_ANY_ID || id->device == device->id_device))
  38                 return id;
  39         return NULL;
  40 }
  41
  42 static const struct ipack_device_id *
  43 ipack_match_id(const struct ipack_device_id *ids, struct ipack_device *idev)
  44 {
  45         if (ids) {
  46                 while (ids->vendor || ids->device) {
  47                         if (ipack_match_one_device(ids, idev))
  48                                 return ids;
  49                         ids++;
  50                 }
  51         }
  52         return NULL;
  53 }
  54
  55 static int ipack_bus_match(struct device *dev, struct device_driver *drv)
  56 {
  57         struct ipack_device *idev = to_ipack_dev(dev);
  58         struct ipack_driver *idrv = to_ipack_driver(drv);
  59         const struct ipack_device_id *found_id;
  60
  61         found_id = ipack_match_id(idrv->id_table, idev);
  62         return found_id ? 1 : 0;
  63 }
  64
  65 static int ipack_bus_probe(struct device *device)
  66 {
  67         struct ipack_device *dev = to_ipack_dev(device);
  68         struct ipack_driver *drv = to_ipack_driver(device->driver);
  69
  70         if (!drv->ops->probe)
  71                 return -EINVAL;
  72
  73         return drv->ops->probe(dev);
  74 }
  75
  76 static int ipack_bus_remove(struct device *device)
  77 {
  78         struct ipack_device *dev = to_ipack_dev(device);
  79         struct ipack_driver *drv = to_ipack_driver(device->driver);
  80
  81         if (!drv->ops->remove)
  82                 return -EINVAL;
  83
  84         drv->ops->remove(dev);
  85         return 0;
  86 }
  87
  88 #ifdef CONFIG_HOTPLUG
  89
  90 static int ipack_uevent(struct device *dev, struct kobj_uevent_env *env)
  91 {
  92         struct ipack_device *idev;
  93
  94         if (!dev)
  95                 return -ENODEV;
  96
  97         idev = to_ipack_dev(dev);
  98
  99         if (add_uevent_var(env,
 100                            "MODALIAS=ipack:f%02Xv%08Xd%08X", idev->id_format,
 101                            idev->id_vendor, idev->id_device))
 102                 return -ENOMEM;
 103
 104         return 0;
 105 }
 106
 107 #else /* !CONFIG_HOTPLUG */
 108
 109 #define ipack_uevent NULL
 110
 111 #endif /* !CONFIG_HOTPLUG */
 112
 113 #define ipack_device_attr(field, format_string)                         \
 114 static ssize_t                                                          \
 115 field##_show(struct device *dev, struct device_attribute *attr,         \
 116                 char *buf)                                              \
 117 {                                                                       \
 118         struct ipack_device *idev = to_ipack_dev(dev);                  \
 119         return sprintf(buf, format_string, idev->field);                \
 120 }
 121
 122 static ssize_t id_show(struct device *dev,
 123                        struct device_attribute *attr, char *buf)
 124 {
 125         unsigned int i, c, l, s;
 126         struct ipack_device *idev = to_ipack_dev(dev);
 127
 128
 129         switch (idev->id_format) {
 130         case IPACK_ID_VERSION_1:
 131                 l = 0x7; s = 1; break;
 132         case IPACK_ID_VERSION_2:
 133                 l = 0xf; s = 2; break;
 134         default:
 135                 return -EIO;
 136         }
 137         c = 0;
 138         for (i = 0; i < idev->id_avail; i++) {
 139                 if (i > 0) {
 140                         if ((i & l) == 0)
 141                                 buf[c++] = '\n';
 142                         else if ((i & s) == 0)
 143                                 buf[c++] = ' ';
 144                 }
 145                 sprintf(&buf[c], "%02x", idev->id[i]);
 146                 c += 2;
 147         }
 148         buf[c++] = '\n';
 149         return c;
 150 }
 151
 152 static ssize_t
 153 id_vendor_show(struct device *dev, struct device_attribute *attr, char *buf)
 154 {
 155         struct ipack_device *idev = to_ipack_dev(dev);
 156         switch (idev->id_format) {
 157         case IPACK_ID_VERSION_1:
 158                 return sprintf(buf, "0x%02x\n", idev->id_vendor);
 159         case IPACK_ID_VERSION_2:
 160                 return sprintf(buf, "0x%06x\n", idev->id_vendor);
 161         default:
 162                 return -EIO;
 163         }
 164 }
 165
 166 static ssize_t
 167 id_device_show(struct device *dev, struct device_attribute *attr, char *buf)
 168 {
 169         struct ipack_device *idev = to_ipack_dev(dev);
 170         switch (idev->id_format) {
 171         case IPACK_ID_VERSION_1:
 172                 return sprintf(buf, "0x%02x\n", idev->id_device);
 173         case IPACK_ID_VERSION_2:
 174                 return sprintf(buf, "0x%04x\n", idev->id_device);
 175         default:
 176                 return -EIO;
 177         }
 178 }
 179
 180 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 181                              char *buf)
 182 {
 183         struct ipack_device *idev = to_ipack_dev(dev);
 184
 185         return sprintf(buf, "ipac:f%02Xv%08Xd%08X", idev->id_format,
 186                        idev->id_vendor, idev->id_device);
 187 }
 188
 189 ipack_device_attr(id_format, "0x%hhu\n");
 190
 191 static struct device_attribute ipack_dev_attrs[] = {
 192         __ATTR_RO(id),
 193         __ATTR_RO(id_device),
 194         __ATTR_RO(id_format),
 195         __ATTR_RO(id_vendor),
 196         __ATTR_RO(modalias),
 197 };
 198
 199 static struct bus_type ipack_bus_type = {
 200         .name      = "ipack",
 201         .probe     = ipack_bus_probe,
 202         .match     = ipack_bus_match,
 203         .remove    = ipack_bus_remove,
 204         .dev_attrs = ipack_dev_attrs,
 205         .uevent    = ipack_uevent,
 206 };
 207
 208 struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
 209                                             const struct ipack_bus_ops *ops)
 210 {
 211         int bus_nr;
 212         struct ipack_bus_device *bus;
 213
 214         bus = kzalloc(sizeof(struct ipack_bus_device), GFP_KERNEL);
 215         if (!bus)
 216                 return NULL;
 217
 218         bus_nr = ida_simple_get(&ipack_ida, 0, 0, GFP_KERNEL);
 219         if (bus_nr < 0) {
 220                 kfree(bus);
 221                 return NULL;
 222         }
 223
 224         bus->bus_nr = bus_nr;
 225         bus->parent = parent;
 226         bus->slots = slots;
 227         bus->ops = ops;
 228         return bus;
 229 }
 230 EXPORT_SYMBOL_GPL(ipack_bus_register);
 231
 232 static int ipack_unregister_bus_member(struct device *dev, void *data)
 233 {
 234         struct ipack_device *idev = to_ipack_dev(dev);
 235         struct ipack_bus_device *bus = data;
 236
 237         if (idev->bus_nr == bus->bus_nr)
 238                 ipack_device_unregister(idev);
 239
 240         return 1;
 241 }
 242
 243 int ipack_bus_unregister(struct ipack_bus_device *bus)
 244 {
 245         bus_for_each_dev(&ipack_bus_type, NULL, bus, ipack_unregister_bus_member);
 246         ida_simple_remove(&ipack_ida, bus->bus_nr);
 247         kfree(bus);
 248         return 0;
 249 }
 250 EXPORT_SYMBOL_GPL(ipack_bus_unregister);
 251
 252 int ipack_driver_register(struct ipack_driver *edrv, struct module *owner,
 253                           const char *name)
 254 {
 255         edrv->driver.owner = owner;
 256         edrv->driver.name = name;
 257         edrv->driver.bus = &ipack_bus_type;
 258         return driver_register(&edrv->driver);
 259 }
 260 EXPORT_SYMBOL_GPL(ipack_driver_register);
 261
 262 void ipack_driver_unregister(struct ipack_driver *edrv)
 263 {
 264         driver_unregister(&edrv->driver);
 265 }
 266 EXPORT_SYMBOL_GPL(ipack_driver_unregister);
 267
 268 static u16 ipack_crc_byte(u16 crc, u8 c)
 269 {
 270         int i;
 271
 272         crc ^= c << 8;
 273         for (i = 0; i < 8; i++)
 274                 crc = (crc << 1) ^ ((crc & 0x8000) ? 0x1021 : 0);
 275         return crc;
 276 }
 277
 278 /*
 279  * The algorithm in lib/crc-ccitt.c does not seem to apply since it uses the
 280  * opposite bit ordering.
 281  */
 282 static u8 ipack_calc_crc1(struct ipack_device *dev)
 283 {
 284         u8 c;
 285         u16 crc;
 286         unsigned int i;
 287
 288         crc = 0xffff;
 289         for (i = 0; i < dev->id_avail; i++) {
 290                 c = (i != 11) ? dev->id[i] : 0;
 291                 crc = ipack_crc_byte(crc, c);
 292         }
 293         crc = ~crc;
 294         return crc & 0xff;
 295 }
 296
 297 static u16 ipack_calc_crc2(struct ipack_device *dev)
 298 {
 299         u8 c;
 300         u16 crc;
 301         unsigned int i;
 302
 303         crc = 0xffff;
 304         for (i = 0; i < dev->id_avail; i++) {
 305                 c = ((i != 0x18) && (i != 0x19)) ? dev->id[i] : 0;
 306                 crc = ipack_crc_byte(crc, c);
 307         }
 308         crc = ~crc;
 309         return crc;
 310 }
 311
 312 static void ipack_parse_id1(struct ipack_device *dev)
 313 {
 314         u8 *id = dev->id;
 315         u8 crc;
 316
 317         dev->id_vendor = id[4];
 318         dev->id_device = id[5];
 319         dev->speed_8mhz = 1;
 320         dev->speed_32mhz = (id[7] == 'H');
 321         crc = ipack_calc_crc1(dev);
 322         dev->id_crc_correct = (crc == id[11]);
 323         if (!dev->id_crc_correct) {
 324                 dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
 325                                 id[11], crc);
 326         }
 327 }
 328
 329 static void ipack_parse_id2(struct ipack_device *dev)
 330 {
 331         __be16 *id = (__be16 *) dev->id;
 332         u16 flags, crc;
 333
 334         dev->id_vendor = ((be16_to_cpu(id[3]) & 0xff) << 16)
 335                          + be16_to_cpu(id[4]);
 336         dev->id_device = be16_to_cpu(id[5]);
 337         flags = be16_to_cpu(id[10]);
 338         dev->speed_8mhz = !!(flags & 2);
 339         dev->speed_32mhz = !!(flags & 4);
 340         crc = ipack_calc_crc2(dev);
 341         dev->id_crc_correct = (crc == be16_to_cpu(id[12]));
 342         if (!dev->id_crc_correct) {
 343                 dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
 344                                 id[11], crc);
 345         }
 346 }
 347
 348 static int ipack_device_read_id(struct ipack_device *dev)
 349 {
 350         u8 __iomem *idmem;
 351         int i;
 352         int ret = 0;
 353
 354         ret = dev->bus->ops->map_space(dev, 0, IPACK_ID_SPACE);
 355         if (ret) {
 356                 dev_err(&dev->dev, "error mapping memory\n");
 357                 return ret;
 358         }
 359         idmem = dev->id_space.address;
 360
 361         /* Determine ID PROM Data Format.  If we find the ids "IPAC" or "IPAH"
 362          * we are dealing with a IndustryPack  format 1 device.  If we detect
 363          * "VITA4 " (16 bit big endian formatted) we are dealing with a
 364          * IndustryPack format 2 device */
 365         if ((ioread8(idmem + 1) == 'I') &&
 366                         (ioread8(idmem + 3) == 'P') &&
 367                         (ioread8(idmem + 5) == 'A') &&
 368                         ((ioread8(idmem + 7) == 'C') ||
 369                          (ioread8(idmem + 7) == 'H'))) {
 370                 dev->id_format = IPACK_ID_VERSION_1;
 371                 dev->id_avail = ioread8(idmem + 0x15);
 372                 if ((dev->id_avail < 0x0c) || (dev->id_avail > 0x40)) {
 373                         dev_warn(&dev->dev, "invalid id size");
 374                         dev->id_avail = 0x0c;
 375                 }
 376         } else if ((ioread8(idmem + 0) == 'I') &&
 377                         (ioread8(idmem + 1) == 'V') &&
 378                         (ioread8(idmem + 2) == 'A') &&
 379                         (ioread8(idmem + 3) == 'T') &&
 380                         (ioread8(idmem + 4) == ' ') &&
 381                         (ioread8(idmem + 5) == '4')) {
 382                 dev->id_format = IPACK_ID_VERSION_2;
 383                 dev->id_avail = ioread16be(idmem + 0x16);
 384                 if ((dev->id_avail < 0x1a) || (dev->id_avail > 0x40)) {
 385                         dev_warn(&dev->dev, "invalid id size");
 386                         dev->id_avail = 0x1a;
 387                 }
 388         } else {
 389                 dev->id_format = IPACK_ID_VERSION_INVALID;
 390                 dev->id_avail = 0;
 391         }
 392
 393         if (!dev->id_avail) {
 394                 ret = -ENODEV;
 395                 goto out;
 396         }
 397
 398         /* Obtain the amount of memory required to store a copy of the complete
 399          * ID ROM contents */
 400         dev->id = kmalloc(dev->id_avail, GFP_KERNEL);
 401         if (!dev->id) {
 402                 dev_err(&dev->dev, "dev->id alloc failed.\n");
 403                 ret = -ENOMEM;
 404                 goto out;
 405         }
 406         for (i = 0; i < dev->id_avail; i++) {
 407                 if (dev->id_format == IPACK_ID_VERSION_1)
 408                         dev->id[i] = ioread8(idmem + (i << 1) + 1);
 409                 else
 410                         dev->id[i] = ioread8(idmem + i);
 411         }
 412
 413         /* now we can finally work with the copy */
 414         switch (dev->id_format) {
 415         case IPACK_ID_VERSION_1:
 416                 ipack_parse_id1(dev);
 417                 break;
 418         case IPACK_ID_VERSION_2:
 419                 ipack_parse_id2(dev);
 420                 break;
 421         }
 422
 423 out:
 424         dev->bus->ops->unmap_space(dev, IPACK_ID_SPACE);
 425
 426         return ret;
 427 }
 428
 429 struct ipack_device *ipack_device_register(struct ipack_bus_device *bus,
 430                                            int slot)
 431 {
 432         int ret;
 433         struct ipack_device *dev;
 434
 435         dev = kzalloc(sizeof(struct ipack_device), GFP_KERNEL);
 436         if (!dev)
 437                 return NULL;
 438
 439         dev->dev.bus = &ipack_bus_type;
 440         dev->dev.release = ipack_device_release;
 441         dev->dev.parent = bus->parent;
 442         dev->slot = slot;
 443         dev->bus_nr = bus->bus_nr;
 444         dev->bus = bus;
 445         dev_set_name(&dev->dev,
 446                      "ipack-dev.%u.%u", dev->bus_nr, dev->slot);
 447
 448         if (bus->ops->set_clockrate(dev, 8))
 449                 dev_warn(&dev->dev, "failed to switch to 8 MHz operation for reading of device ID.\n");
 450         if (bus->ops->reset_timeout(dev))
 451                 dev_warn(&dev->dev, "failed to reset potential timeout.");
 452
 453         ret = ipack_device_read_id(dev);
 454         if (ret < 0) {
 455                 dev_err(&dev->dev, "error reading device id section.\n");
 456                 kfree(dev);
 457                 return NULL;
 458         }
 459
 460         /* if the device supports 32 MHz operation, use it. */
 461         if (dev->speed_32mhz) {
 462                 ret = bus->ops->set_clockrate(dev, 32);
 463                 if (ret < 0)
 464                         dev_err(&dev->dev, "failed to switch to 32 MHz operation.\n");
 465         }
 466
 467         ret = device_register(&dev->dev);
 468         if (ret < 0) {
 469                 kfree(dev->id);
 470                 kfree(dev);
 471                 return NULL;
 472         }
 473
 474         return dev;
 475 }
 476 EXPORT_SYMBOL_GPL(ipack_device_register);
 477
 478 void ipack_device_unregister(struct ipack_device *dev)
 479 {
 480         device_unregister(&dev->dev);
 481 }
 482 EXPORT_SYMBOL_GPL(ipack_device_unregister);
 483
 484 static int __init ipack_init(void)
 485 {
 486         ida_init(&ipack_ida);
 487         return bus_register(&ipack_bus_type);
 488 }
 489
 490 static void __exit ipack_exit(void)
 491 {
 492         bus_unregister(&ipack_bus_type);
 493         ida_destroy(&ipack_ida);
 494 }
 495
 496 module_init(ipack_init);
 497 module_exit(ipack_exit);
 498
 499 MODULE_AUTHOR("Samuel Iglesias Gonsalvez <siglesias@igalia.com>");
 500 MODULE_LICENSE("GPL");
 501 MODULE_DESCRIPTION("Industry-pack bus core");